This might be the wrong topic header selection, but I am hoping there is a way to use an analog mixer to send audio into A3, and split them back out into different channels using like a Demux node or something else and then send to effects? I am essentially trying to make due with what I have, rather than buying a rack and ES-9. @futureaztec kinda made me start thinking, is there any way that I can do my current hardware setup and use A3 (or A4 upcoming) to pipe like 3-4 channels of audio, mixed together and then separate it back into individual channels? In an ideal, perfect world, I was hoping I could do this to process effects separately and then re-mix (in the traditional, combinational sense) before heading to the DAW or output. This is kinda like a transitional phase before I spring $700-800 for a rack mounted DC coupled interface with the exact capability I am looking for. I am betting if anyone can help me make this happen, it is gonna be @robertsyrett, @stschoen, or @biminiroad. I kinda feel like this is probably not possible, but there is still a small amount of hope that it can be done somehow…
Unfortunately once audio channels are mixed together there really isn’t a good way to separate them back out cleanly SFAIK. There are some plug-ins that will isolate a vocal or percussion track using a mix of dynamic filtering and phase analysis, but the results are uneven at best. Practically speaking, you are limited to however many channels your interface provides. You could of course look for a standalone multichannel audio interface that’s not DC coupled and will work with the iPad. I use a Focusrite Scarlett 6i6 on my Mac and it works fine with the iPad. You might find a good price on a gen 2 version since gen 3 is now out.
@stschoen I’m looking at the NI Komplete Audio 6 MK II as a potential contender to take the place of my AudioBox iTwo. There is no DC-coupled inputs, but the outs are DC and there is 4 of them, seemingly each TRS, if I am reading the specs correctly. That could be two modulation signals or a gate and pitch for each one. That seems pretty good, and then you get 4 TRS inputs also, just no DC coupled, as mentioned above. Still it seems pretty good for $250. What do you think?
That’s pretty cool. Not a bad compromise for $250. You’re really much more likely to use CV out of Audulus than CV in. Although the voltage swing is only +/- 2 volts rather than 10, it would still give you the ability to send CV out of Audulus to your synths as well as give you 4 to 6 inputs and outputs plus some mic preamps. I didn’t think the SPDIF I/O on my Focusrite would be useful when I bought it, but my UltraNova has SPDIF out and I bought a cheap SPDIF to analog box from Amazon to use the SPDIF output from the Focusrite, so in the end I’m using both SPDIF in and out. All things considered, this would be a good intermediate step and might even be enough to meet your needs long term
I read some not so good things about the NI customer support, as well as the software having some incompatibility issues with Mac AND Windows, some design flaws that were making a lot of people very unhappy, and decided that I should look elsewhere.
Then I stumbled upon this, and after scouring the web reading every review I could find, I decided that even though this lacks the S-PDIF I/O that the KA 6 has, this just seemed like a better bet. It still has the DC coupled outs, and it also has a 5 star across the board rating on Amazon, Sweetwater, and a couple other sites I looked.
I think this will turn out to be the next best thing to buying a rack and a ES-9 (which I still may do in the future, but I don’t want to do that until I am sure about it being a necessity for me). Thanks for your advice and assistance, as always! 
I have always thought that NI’s software wasn’t particularly user friendly, but I haven’t had any experience with their hardware. I rate customer support as very important and would avoid companies with a bad rep in that area. The MOTU unit looks pretty sweet. A lot of features for the price and pretty good specs. I really like the front panel meters, wish my Focusrite had something similar. It’s class compliant and will run on iOS using a CCK. Since it’s bus powered, you will need to use the newer CCK that provides a power input as well as a USB port to use it with the iPad. I always run my iPad on power when using it for music stuff in any case to avoid unexpected battery issues.